Fluid heating apparatus



2 Sheets-Sheet 1 R. B. MILDON FLUID HEATING APPARATUS 1 Filed June 4, 1936 March 15, 1938.

March 15; 1938. R, B MILDON FLUID HEATING APPARATUS Filed June 4, 1936 2 Sheets-Sheet 2 INVENTOR Realm-11.0 B. MILDON.

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Patented Mar. 15, 1938 i a 2,11 9% UNITED STATES PATENT GFFICE FLUID HEATING APPARATUS Reginald B. Mildon, Lansdowne, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Fa, a corporation of Pennsylvania Application June 4, 1936, Serial No. 83,423

11 Glaims. (Cl. 122-30) My invention relates to fluid heaters of the sponding walls 2| and 22'. Ihe radial walls are type disclosed in the copending application of joined at their inner ends as shown at 23 and 23' It. A. Foresrnan, Serial No. $58,336:, filed Februand divide the circular heating structure into dr 24, 9 and it has for an object to provide arcuate chambers 24 and 25; the former comprisimproved apparatus of this kind. ing a combustion space and the latter a fuel A further object of my invention is to promagazine. The portion 25 of the wall it which vide an improved fluid heater of the type having defines the outer wall of the magazine 25 may a rotatable annular grate with a magazine arbe of a single thickness of material and need ranged above the grate to feed the fuel gravinot be cooled as it is not subjected to the high {10 tationally to the grate and in which fluid heater temperatures prevailing in the combustion charnthe air for combustion is preheated before being her. 7 supplied to the grate. As the walls 21 and 22 of the fuel magazine A still further object of my invention is to pro- 25 are subjected to the high temperature prevail.- vide a fluid heater of the foregoing character ing in the combustion chamber, it is advisable wherein the walls of the magazine-disposed above that they be cooled and some means such as, 15 the grate are air-cooled so as to insure against for example, a blower 3b is provided for circuobjectionable heating of the -f uel contained in lating air between the walls 2i and 21' and the the magazine. walls 22 and 22 respectively. Further reference EIPhese and other objects are effected by my lnto the cooling of the .walls 2! and 22 and to the yention, as will be apparent from the following translation of the air by the blower ,319 will be 20 description and claims taken in connection with made hereinafter.

the accompanying drawings, in which: The structure 9 is preferably supported on a isis a plan V w o my imp oved f u as :2 hav n outer an nn Wall m mb r h at and 28. An annular grate structure 29 is rotat- 3;, F 2 s a Sectional View taken along the line ably supported by the base 25 as best shown in 25 II-. ofF g. Fig. 3. The grate 29 defines the bottom of the Fig. 3 :isa vertical section taken along the line combustion chamber g9 and the fuel magazine III-:III of Fig. 2; 25. Goal ;from the magazine 25 is, therefore, fed Fig. {l is a sectional view taken along the line by gravity to the grate. Rotation o t gra e lib lvwliv of i 29 may be effected inanysuitable manner as, by

Fig. 5 is a section taken along the line V--V a pawl andratchet mechanism shown atBZi in OfFig. Fig. 6. The latter mechanism may include a "6 is a sectional view of a portion of the pawltd carried by a shaft which is oscillated apparatus shown in Fig. .5 and ,is taken along in any-suitable manner. The pawl 3d en g s a the :line VtI.-..'.Vl thereof; ratchet 135 formed on the underside of the grate 35 Fig. 27 is a front elevation of the heater; and, structure 28?, so that as the shaft $5 is oscillated, Fig. 8 is a fragmentary section taken along the pawl 35 advances the grate 29 step .by step the line VI1IVI1I,of Fig 2. and in clockwise direction, as viewed in Fig. 2. Referring now to the various figures of the The shaft 3 5 is operated periodically in response 9 drawings, fluid, such as, for example, water is to demands for heat, all as is well understood in v4U heated in a structure 9 having outer spaced :walls the automatic heating art. Preferably, the-blow- .IB and l l and an inner column I; forming, reerili' and the shaft 35 are simultaneously operspectively, water spaces l3 and Ml. A hollow ated so that air is translated to the grate 29 by baiile member l5 connects the inner column E2 the blower 3!) only during periods when the a 4:, and the wall H and provides ,a communicating is operated. a

space it between the water spaces is and it. A As shown in Fig. 4, the base 2% is divided by conduit 1 l admits water to the space 53 .andthe radial walls 31!, 38, and;3 9 forming a windbox ll heated water or vapor .is discharged through andan ash receivingchamber 52. The walls 31, conduits LB and 19 located near the toppf the 38, and 39 extend from the bottom of the base if) hea 25 to the top thereof and provide a further sup- The portion or" the wall iii adjacentthe water port for the grate 29. An additional Wall 3 m y space I3 is arcuate in shape as best shown in extend radially of the windboxl for supporting F e- 2 th ends ef e a c at po t on in th at 9 andi cl de w r en g M for D radial walls 2! and 22 secured thereto. spaced sage of combustion air. The upper edges of the rom th at all r s ecti e y are corre- Wel 113 3 9 5 ar r al s a ho a 45 in Fig. 6, for providing suitable bearing surfaces for the grate and for sealing the windbox 4| and chamber 42. This form of seal is well known in the art and is described in the aforementioned application of R. A. Foresman.

The ash receiving chamber 42 is provided with a receptacle 4'! for ash discharged from the grate 29. Further reference to the discharge of ash will be made hereinafter. A hinged door 48 is provided for access to the receptacle 4?.

As shown in Fig. 3, the wall members 2| and 2| of the magazine 25 extend downwardly toward the base 26 and terminate adjacent the upper surface of the grate. They are closed at their lower ends, as shown at'50 except for an opening 5| located at the outer end thereof and communicating with the windbox 4|. In order to feed fuel from the magazine to the combustion chamber, a suitable opening or passage 53 extends through the walls 2| and 2|. As the bottom of the magazine is wider than the grate 29, sloping plates 54 and 55 are provided for directing the fuel onto the grate 29 as best shown in Figs. 2 and 3.

An ash discharge opening 56 is provided in the outer walls l and II adjacent the magazine wall 22. The ash is deflected outwardly of the grate 29 by a plate 57 secured to the structure 9 in any suitable manner. As shown, the plate 51 is secured to the inner column l2 and to the wall I this plate 51 being preferably arranged at a tangent to the grate for facilitating the radial movement of ash as the grate rotates. It will be apparent that ash deflected from the grate falls over the periphery of the grate into the container 41.

The structure 9 may include a top wall 58 having an outlet 59 for products of combustion, as shown in Fig. 1. The outlet 59 is connected to a suitable flue, not shown, for the discharge of the products of combustion. An arch structure 6| may be disposed in the combustion chamber 24, as best shown in Figs. 1 and 3, which arch structure extends from the wall 2| to the line 6| (Fig. so as to lengthen the path of gas travel from the grate to the outlet 59.

Fuel is admitted to the magazine 25 in any suitable manner as through a door opening 62 formed in the wall 26. In order to further protect the walls 2| and 22 from the heat of combustion, they may be lined with suitable refractory as shown at 65 and 66, respectively.

In order to operate the foregoing heater, the magazine is filled with coal and the shaft 35 is oscillated. Oscillation of the shaft 35 actuates the pawl and ratchet mechanism 33 which rotates the grate 29, whereupon fuel from the magazine passes through the opening 53 into the combustion chamber. The fuel is levelled by the upper edge of the opening 53 so that the bed of fuel is maintained at a predetermined uniform thickness as it enters the chamber 24. Ignition is effected adjacent the wall 2| and the fuel is progressively burned as it slowly rotates with the grate through the combustion chamber 24, combustion being completed at some point between the wall 2| and the plate dependent upon the load on the boil-- er. The refuse is deflected outwardly by the plate 51 as the grate 29 advances therebeneath, and the refuse drops over the outer edge of the grate into the receptacle 41.

Air for supporting combustion is drawn from the surrounding atmosphere through the inlet 39 of the blower 3|! and is discharged between the walls 22 and 22' and thence the walls 2| and.

2|. In its passage between these walls, the air is preheated. The heated air travels downwardly between the walls 2| and 2| and thence through the opening 5| into the windbox 4|. The walls 2| and 22 are thereby effectively cooled and the combustion supporting air is preheated so that the combustion efficiency of the furnace and its reliability are improved.

During periods when there is no demand for additional heat and the shaft and the blower are inactive, the supply of air to the grate is substantially reduced. At this time, the outlet 59 being connected to a suitable flue, there is a circulation of air by natural draft which is sufficient to cool the walls 2| and 22 and to maintain combustion.

From the foregoing, it will be apparent that I have provided an improved fluid heater of the annular grate type wherein the fuel magazine walls are effectively cooled and the combustion supporting air is preheated, thereby increasing the efficiency of the fluid heater.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. In fluid heating apparatus, the combination of a rotatable grate, an outer wall structure disposed above the grate and embodying a space for fluid to be heated, a pair of wall structures joined at their inner ends adjacent the central portion of the grate and extending transversely of the grate, said transversely extending walls and a portion of the outer wall defining a magazine for the gravitational feeding of fuel to the grate and one or more of the transversely extending wall structures having a passage formed therein, and means for admitting air to said passage.

2. In fluid heating apparatus, the combination of a rotatable grate, an outer wall structure disposed above the grate and embodying a space for fluid to be heated, a pair of wall structures joined at their inner ends adjacent the central portion of the grate and extending transversely of the grate, said transversely extending walls and a portion of the outer wall defining a magazine for the gravitational feeding of fuel to the grate and one or more of the transversely extending wall structures having a passage formed therein, means for admitting air to said passage, and means for conducting the air from the passage to the combustion chamber for supporting combustion.

3. In fluid heating apparatus, the combination of a rotatable grate, an outer wall structure disposed above the grate and embodying a space for fluid to be heated, a pair of wall structures joined at their inner ends adjacent the central portion of the grate and extending transversely of the grate, said transversely extending walls and a portion of the outer wall defining a magazine for the gravitational feeding of fuel to the grate and one or more of the transversely extending wall structures having a passage formed therein, means for admitting air to said passage, and means for conducting air from the passage in said transversely extending wall structures to the underside of the grate.

4, In fluid heating apparatus, the combination of a rotatable annular grate, an outer wall having spaces therein for the medium to be heated and arranged above the perimeter of the grate, first and second circumferentially spaced walls extending inwardly from the outer wall and joined at their inner ends for defining a fuel magazine above an arcuate portion of the grate, the remaining portion of the grate defining a combustion chamber, said first circumferentially spaced wall having a portion thereof spaced above the grate and defining, therewith, a fuel discharge orifice, and said second circumferentially spaced Wall terminating adjacent to the grate, a passage formed in said circumferentially spaced walls for the circulation of air therethrough, and means for admitting air to the passages in the circumferentially spaced walls for cooling the same.

5. The combination as claimed in claim 4 wherein at least one of said circumferentially spaced walls includes a layer of refractory on the side thereof adjacent the combustion chamber.

6. In fluid heating apparatus, the combination of a rotatable annular grate, a structure arranged above the grate and having spaces formed therein for fluid to be heated, said structure defining a combustion chamber above an arcuate portion of the grate, a magazine for fuel disposed above a second arcuate portion of the grate and including first and second walls spaced circumferentially with respect to the grate and joined at their inner ends, said first and second magazine Walls having passages formed therein, said first magazine wall being spaced above the grate for defining, therewith, a fuel discharge opening, means for rotating the grate, means for admitting fuel to the magazine so that it passes through said opening as the grate is rotated, means for passing air through the passages of the magazine walls for cooling the same and means for conveying the heated air from said passages to the grate.

7. In fluid heating apparatus, the combination of a rotatable annular grate, a base member for supporting the grate and defining a windbox beneath an arcuate portion of the grate, a boiler structure carried by the base member and including a wall disposed above the periphery of the grate, said wall having a space therein for water to be heated and defining a combustion chamber above said arcuate portion of the grate, a magazine for fuel disposed above a second arcuate portion of the grate and including first and second walls joined at their inner ends and extending transversely of the grate, said first and second magazine walls having a passage formed therein, said first magazine wall having its bottom portion spaced above the grate for defining therewith a fuel discharge orifice, means disposed adjacent the second magazine wall for deflecting ash radially from the grate, means for rotating the grate, means for admitting fuel to the magazine for passage through the orifice as the grate is rotated, and means for translating air for supporting combustion through the passage of the magazine walls and thence to said windbox, whereby the magazine walls are cooled and the combustion supporting air is heated prior to its passage through the grate.

8. In fluid heating apparatus, the combination of a rotatable annular grate, a wall arranged above a portion of the periphery of the grate and having a space formed therein for fluid to be heated, said wall defining a combustion chamber above an arcuate portion of the grate, a magazine for fuel disposed adjacent a second portion of the periphery of the grate and having at least a portion thereof above a'second arcuate portion of the grate, said magazine including first and second circumferentially spaced walls extending transversely of the grate and joined at their inner ends, said magazine including an outer wall connecting the outer ends of the circumferentially spaced walls, at least a portion of said magazine walls having a jacket formed therein, said first magazine wall having a portion thereof spaced vertically from the grate for defining a fuel discharge orifice, means for rotating the grate, means for admitting fuel to the magazine to be passed through said orifice into the combustion chamber as the grate is rotated and means for translating air for combustion through said jacket and thence to a portion of the underside of the grate, whereby the magazine walls are cooled and the combustion supporting air is heated prior to its passage through the grate.

9. In fluid heating apparatus, the combination of a rotatable circular grate, a fluid heating structure disposed above the grate and having wall members defining a combustion chamber above a segment of the grate, said wall members having spaces therein for fluid to be heated and a magazine for fuel elevated with respect to a second segment of the grate for delivering fuel by gravity thereto, said magazine including circumferentially spaced means extending transversely of the grate and having a passage formed therein for the circulation of air.

10. In fluid heating apparatus, the combina tion of a rotatable circular grate, a fluid heating structure disposed above the grate and having wall members defining a combustion chamber above a segment of the grate, said wall members having spaces therein for fiuid to be heated, a magazine for fuel elevated With respect to a second segment of the grate for delivering fuel by gravity thereto, said magazine including circumferentially spaced means extending transversely of the grate and having a passage formed there- 1n, and means for translating air through said passage to the grate for supporting combustion thereon.

11. In fluid heating apparatus, the combination of a rotatable circular grate, a fluid heating structure disposed above the grate and having Wall members defining a combustion chamber above a segment of the grate, said wall members having spaces therein for fluid to be heated, a magazine for fuel elevated with respect to a second segment of the grate for delivering fuel by gravity thereto, said magazine including first and second means extending transversely of the grate and having an air passage formed therein, one of said transversely extending means being spaced above the grate for defining an opening for the passage of fuel from the magazine to the combustion chamber and means for admitting air to said air passage.

REGINALD B. MILDON. 

